Leakproof carton



NOV. 23, 1965 R M HOLMES 3,219,255

LEAKPROOF CARTON Filed March '7, 1965 FIG. 8

INVENTOR. RAYNOR M. HOLMES Ig/M w ATTORN S United States Patent O 3,219,255 LEAKPROOF CARTON Raynor M. Holmes, Newark, N.Y., assignor to Riegel Paper Corporation, New York, N.Y., a corporation of Delaware Filed Mar. 7, 1963, Ser. No. 263,666 2 Claims. (Cl. 229-39) The present invention relates to leakproof fibrous cartons and more particularly to an improvement in the end construction thereof, which construction affords a simple, yet highly efficient, means for tightening the corners and controlling the leakage in such cartons.

Specifically, the present invention relates to a new and improved folding carton, especially adapted for packaging ice cream, which incorporates a novel tongue and groove end panel arrangement which cooperates to form and maintain a pair of tight corner seals, which seals prevent the leakage of melted ice cream therethrough. A further aspect of the invention is the provision of improved corner sealing means in combination with conventionally locking carton end flaps to form a new and improved end closure for an ice cream carton or the like.

Another important aspect of the invention resides in the improvement in the overall carton rigidity, as compared to conventional cartons of this type, contributed by the tongue and groove closure of the present invention.

To understand more completely the nature of the present invention, reference should be had to the following detailed description, taken in conjunction with the accompanying drawing in which:

FIG. l is a plan view of a one-piece blank cut, scored and ready for erection into a carton embodying the principles of the present invention;

FIG. 2 is a perspective view showing the carton erected and ready for leakproof end closure with the new and improved tongue and groove structure of the present invention;

FIG. 3 is an end view of the end closure structure of the carton; and

FIG. 4 is an enlarged, fragmentary cross-sectional view of the carton of FIG. 3 taken along line 4-4 thereof.

The invention is embodied in the present instance in a container made from a blank 9, such as shown in FIG. 1, cut from paperboard stock =or a like sheet material. Advantageously, the material is treated so as to be substantially impervious to moisture and liquid.

As shown in FIG. l, the blank 9 is scored longitudinally and transversely to form bottom, front and back wall panels 11, 12 and 13, respectively, and a cover panel 14, which in the present instance is rectangularly shaped so as to produce a straight-walled container when erected. The bottom panel 11 is provided at opposite ends thereof with inner end panels 15, 16, articulated along score lines a, 16a, while the cover panel 14 is provided at opposite ends thereof with outer end panels 17, 1S.

Articulated to the opposite ends of the back Wall panel 13 are back locking fiaps 19, 20, while front locking iiaps 21, 22, having locking slits 23, are articulated to the opposite ends of the front wall 12. The free end of the cover panel 14 has a glue flap 24 articulated thereto, which flap includes a transverse score line 25 defining an adhesive portion 26 and an opening portion 27.

In accordance with the present invention, and as shown in FIG. 3, the bottom end panels 15, 16 extend upwardly for the full depth of the carton at its corners only, to define sealing ears 28, 29 at the upper carton corners. The sealing ears define therebetween recesses or grooves 30, 31. The cover outer end panels 17, 18 are special-ly constructed to have corner sealing portions 32, 33 of the ICC full carton width only immediately adjacent the score lines 17a, 18a, while having the remainder of the panel cut away at convergent edges 34', 35' to form tapered tongue portions, 34, 35 of widths not in excess of the widths of the grooves 30, 31. Advantageously, the sealing portions 32, 33 and the sealing ears 28, 29, are, themselves, slightly tapered at convergent edges 32', 33', 28', 29', respectively, to facilitate erection of the carton from the glued blank 9.

The carton contemplated by the present invention is of the end-filling, top-opening type, well known in the art. Accordingly, the blank 9 is initially folded upon itself to form a conventional flat carton tube, which is completed by gluing the flap 24 to the front Wall 12. The end closures may then be completed in the following manner: With the tube squared so as to have a rectangular profile, as shown clearly in FIGS. 2 and 3, the cover end panels 17, 18 and the body end panels 15, 16 are folded inwardly, so that the cover and body end panels interlock, with the tongue portions 34, 35 overlying the lower portions 15', 16 of the body end panels, and with the sealing ears 28, 29 of the body panels overlying the sealing portions 32, 33 of the cover panels 17, 18. The infolding and connection of the front flaps 21, 22 and the rear flaps 19, 20 completes the new and improved end structure.

-'The interlocking end panels create a truss-like effect adjacent the upper corners which significantly increases the rigidity of the carton and the tightness of the corners. Thus, a force normal to the end interlocked panels, which could cause conventional overlapping end panels to be collapsed, is easily resisted by the interlocked tongue and groove end panel construction of the invention. In this respect, the respective tongue and groove flaps advantageously are so proportioned that the sealing ears 28, 29 are of sufficiently short length to retain substantial structural rigidity. By way of specific example, the sealing ears may have a free length of about 5A inch in a carton having a Width of about 4% inches and a depth of about 31/2 inches.

In order to accommodate the cross-folding of the respective tongue and groove flaps, without undesirably bending or distorting either flap, it is advantageous to form short slots or cuts 36 into the body of the groove flaps 15, 16, the slots 36 advantageously being about 1A; inch in length in a carton of the dimensions mentioned above and being aligned substantially with the inner edges of the sealing ears 28, 29. The arrangement is such as to permit the free edges of the groove flaps 15, 16, which contact the tongue flaps 17, 18 in the area of the crossover, to be deflected inward.

As shown in FIG. 4, the upper corners of the erected carton are sealed by a three-ply construction of cover panel sealing portions 32, 33, body panel sealing ears 28, 29, and body flaps 19-22. Substantial improvement is realized over the sealing obtainable with conventional cover panel constructions, which is attributable in part to the unique construction in which the sealing elements at the corners are oppositely disposed from the panels from which they derive their support. Thus, the major portions of the cover end panels 17, 18 overlie the body end panel lower portions 15', 16', while the sealing portions of the cover end panels underlie the sealing ears of the body end panels. Likewise, the major portions of the body end panels underlie the cover end panel tongues 34, 35, while the body panel sealing ears 28, 29 overlie the cover end panel sealing portions 32, 33.

It should be understood that an inward normal force on the cover end panel, the body end panel, -or both, causes the sealing ears to move against the sealing portion to increase the seal therewith due to the novel interlocking tongue and groove construction. A conventional end structure would tend to cave in under such a force and thus decrease any existing seal. However, the truss-like eifect of the new and improved carton resists such a collapse.

The carton of the present invention is intended particularly for use by dairies and the like in mass production ice cream filling applications, in which the filled containers are closed and then conveyed bottom up from the lling station to a freezing or hardening room. Particularly in the warm seasons, the newly filled cartons tend to leak at the corners, in the relatively short interim between iilling and hardening. With the carton end construction of the invention, however, the upper corners of the carton are effectively sealed by a three-ply structure in which the sealing ears 28, 29 are compressed at the upper corners between the sealing portions 32, 33 and the foldedover and locked outer flaps 19-22. Although it is still possible for leakage to occur with the new cart-on, it is conlined to areas remote from the corners of the carton. Thus, such leakage as may occur remains underneath the outer flaps 1922. The advantageous new construction thus prevents the still soft ice cream from leaking out ont-o the printed outer surface of the carton, onto other, adjacent cartons, and onto the equipment, plant oor, etc., as has been the regular experience with conventional cartons.

Although the present invention has been described with reference to a specific, preferred embodiment, it should be understood that the disclosure has been made only by way of example and that certain changes in details of construction and arrangement of the elements may be made without departing from the spirit and scope of the invention as hereinafter claimed.

I claim:

1. A container for ice cream and the like comprising:

(a) contiguous, articulated cover, rear, bottom and front wall panels,

(b) said front and rear panels having side flaps articulated thereto,

(c) a pair of body end panels articulated to opposite ends of said bottom wall panel,

(d) said end panels being of full carton depth only along the end edge portion thereof and being of less than full carton depth along central body portions thereof,

(e) said full depth portions defining a pair of sealing .ears adjacent two corners of each end of the container, and a recess therebetween of predetermined width, said recess being substantially adjacent an edge of the container,

(f) a pair of cover end panels articulated to opposite ends of said cover panel,

(g) said cover end panels having sealing portions of full carton widt-h and having first convergent edges immediately adjacent said cover front panel,

(h) saidY sealing portions having a predetermined depth measured from the outer ends of said lirst convergent edges to said cover panel substantially equal to said depths of said recess,

(i) said cover end panels having second convergent edges providing predetermined tongue portions extending from said sealing portions and having a Width at the intersection of said lirst and second convergent portions not greater than the width of said recesses,

(j) said corner sealing ears overlying said sealing portions at the upper corners of said carton and cooperating therewith to form corner seals having a predetermined eHiciency, and said tongue portions extending through said recesses and overlying said central body portions, whereby inwardly directed forces applied to said tongue portions tend to increase the eiciency of said corner seals, and

(k) said side flaps overlying said cover body end panels.

2. A container in accordance with claim 1, in which W(a) said side aps include non-adhesive locking means for mutually securing said cover and body end panels.

References Cited by the Examiner UNITED STATES PATENTS FRANKLIN T. GARRETT, Primary Examiner. 

1. A CONTAINER FOR ICE CREAM AND THE LIKE COMPRISING: (A) CONTIGUOUS, ARTICULATED COVER, REAR, BOTTOM AND FRONT WALL PANELS, (B) SAID FRONT AND REAR PANELS HAVING SIDE FLAPS ARTICULATED THERETO, (C) A PAIR OF BODY END PANELS ARTICULATED TO OPPOSITE ENDS OF SAID BOTTOM WALL PANEL, (D) SAID END PANELS BEING OF FULL CARTON DEPTH ONLY ALONG THE END EDGE PORTION THEREOF AND BEING OF LESS THAN FULL CARTON DEPTH ALONG CENTRAL BODY PORTIONS THEREOF, (E) SAID FULL DEPTH PORTIONS DEFINING A PAIR OF SEALING EARS ADJACENT TWO CORNERS OF EACH END OF THE CONTAINER, AND A RECESS THEREBETWEEN OF PREDETERMINED WIDTH, SAID RECESS BEING SUBSTANTIALLY ADJACENT AN EDGE OF THE CONTAINER, (F) A PAIR OF COVER END PANELS ARTICULATED TO OPPOSITE ENDS OF SAID COVER PANEL, (G) SAID COVER END PANELS HAVING SEALING PORTIONS OF FULL CARTON WIDTH AND HAVING FIRST CONVERGENT EDGES IMMEDIATELY ADJACENT SAID COVER FRONT PANEL, (H) SAID SEALING PORTIONS HAVING A PREDETERMINED DEPTH MEASURED FROM THE OUTER ENDS OF SAID FIRST CONVERGENT EDGES TO SAID COVER PANEL SUBSTANTIALLY EQUAL TO SAID DEPTHS OF SAID RECESS, (I) SAID COVER END PANELS HAVING SECOND CONVERGENT EDGES PROVIDING PREDETERMINED TONGUE PORTIONS EXTENDING FROM SAID SEALING PORTIONS AND HAVING A WIDTH AT THE INSECTION OF SAID FIRST AND SECOND CONVERGENT PORTIONS NOT GREATER THAN THE WIDTH OF SAID RECESS, (J) SAID CORNER SEALING EARS OVERLYING SAID SEALING PORTIONS AT THE UPPER CORNERS OF SAID CARTON AND COOPERATING THEREWITH TO FORM CORNER SEALS HAVING A PREDETERMINED EFFICIENCY, AND SAID TONGUE PORTIONS EXTENDING THROUGH SAID RECESSES AND OVERLYING SAID CENTRAL BODY PORTIONS, WHEREBY INWARDLY DIRECTED FORCES APPLIED TO SAID TONGUE PORTIONS TEND TO INCREASE THE EFFICIENCY OF SAID CORNER SEALS, AND (K) SAID SIDE FLAPS OVERLYING SAID COVER BODY END PANELS. 